The invention relates to the field of tunable rimless shell-less drums and comprises a lightweight, compact, rimless drum which is easily, conveniently tuned from above without distorting its frame in a way which reduces its tonal quality. The invention permits the making of a truly compact, lightweight, tunable, rimless drum with both convenient, reliable tuning and tone quality so high as to be superior to most traditional shell drums.
Rimless o shell-less drums are drums which can generate their sound with only a drum head and do not use a rim or shell to tune the head. The drum head consists of a membrane and a light frame which is attached to the membrane by adhesives or by mechanically crimping the membrane between two or more hoops which collectively make up the frame. The drum head may be wholly untensioned, or it may be slightly or wholly pretensioned during manufacture to have a defined pitch. Rimless or shell-less drums are dramatically lighter in weight and smaller in size than shell drums, but until the present invention could not match the tonal quality of shell drums and lacked a commercially accepted tuning system.
Traditional shell drums have a cylindrical shell with a membrane, or "batter head", stretched over one or both open ends of the shell. The membrane is retained by a hoop which extends over and about the end of the shell. A counterhoop rests atop the hoop, and this counterhoop is engaged by tension rods which are positioned around the counterhoop and threaded into lugs which are fixed to the outside of the shell. By tightening the tension rods with a small drum key, the hoop and counterhoop, which collectively comprise a frame, are pulled down onto the shell and the membrane is stretched over he edge of the shell until the pitch rises to the desired level. These tension rods have drum key engaging heads positioned around the frame, and confront the seated drummer so as to be fully accessible and visible to him. This traditional tuning system is considered wholly acceptable to drummers as being fast and convenient. Beside the traditional tension rod tuning devices, various modifications and variations have been developed for shell-type drums, some of which are shown in U.S. Pat. Nos. 4,475,434, 3,635,119, 4,218,952, 4,211,144, 4,295,405, 4,122,749 3,279,299, 3,029,679, 3,433,115, 2,433,200, 2,115,741, 4,079,657, and 3,981,220. U.S. Pat. No. 3,482,479 shows a tuning device used with the drum head of a tambourine but accessible only from below and within the tambourine shell.
Traditional shell drums are capable of excellent sound but are heavy, awkward to transport and cumbersome to store. A large shell drum set used in typical orchestral or rock bands can fill the storage capacity of an automobile and require multiple trips between car and stage to set up the instruments. The carrying of shell drums by marching bands can tire even the strongest drummers and limit the mobility and formations available to an otherwise more mobile marching unit.
Recognizing the weight and mobility problems of shell drums, Ralph C. Kester, Jr., in U.S. Pat. No. 3,186,289, issued June 1, 1965, disclosed a more compact, somewhat lighter weight drum for marching bands which utilized a wide rim as a shell substitute. The drum carried a membrane and tuning devices on the inside of the rim. This Kester drum was more mobile than shell drums, but the oversize rim, to be sufficiently rigid for tuning purposes, was still quite heavy, the drum was expensive, and the tuning devices were not easily accessible or convenient to actuate. While the Kester device represented a positive step toward size reduction, these drawbacks severely limited wide commercial acceptance of his drum.
In 1985, Kester, in U.S. Pat. No. 4,520,709, disclosed a lighter weight drum which had a further improved tuning system. In this drum, the tuning devices were placed outside the drum rim so they could now be seen by the seated drummer, but tuning was still awkward and done from below the drum by pushing the drum key upward against tension rods around the rim and then turning the key to force a tuning band against the membrane. During tuning, the key could easily slip off the rods and fall to the floor. Tuning was awkward, slow and hard to accomplish during performances.
Beside being awkward, the Kester tuning structure could deform the drum head frame when it was tightened, and resulting binding or twisting deformation could reduce tonal quality. The tuning device utilized a bracket with a notched portion which grabbed the outer edge of the drum head's frame, and when the bracket was pulled down during tuning to stretch the membrane, the frame could be distorted downwardly and twisted radially inwardly. Deforming the natural circular configuration of the frame always affects the way the drum vibrates and reduces its tonal quality. When the Kester tensioning rod was tightened in the bracket, it could also cause camming or binding between the rod and the unthreaded aperture through which the rod passes, resulting in the Kester hook 30 twisting clockwise and pulling away from the drum's center, thereby allowing the drum frame to be stretched into noncircular configurations and diminishing tonal quality. All such deformation affects the way a drum vibrates and changes its tonal qualities. The complex pillared frame of the Kester structure, while suitable for light drumming, was not designed to withstand heavy, rock drumming, which with its excessive vibration can loosen and rearrange components. The unusual design of the Kester drum also results in its membrane being wholly exposed to damage at the edges, and any striking in that region would cut the membrane. It could not be used for any rimshot type techniques. While lighter in weight, this second Kester drum design, with its complex frame, awkward tuning, exposed membrane and complicated assembly problems did not receive wide commercial acceptance.
Any camming or distorting of the tuning devices, twisting or binding of frame or tuning ring, or movement of the tuning band within the frame can introduce deformation which significantly reduces the drum's natural, rich, full tones. Excessive vibration during heavy, rock-style drumming can produce substantial movement between drum elements, and such unwanted movement must be restricted if full tonal response and consistent pitch are to be obtained with a shell-less or rimless drum. Handling such heavy vibration is also challenging with marching band drums where it is normal practice to tightly tune the drum heads for higher frequencies which seem louder and project more effectively in the large stadium, noisy crowd situations in which marching bands perform. Obtaining the high pitch requires excessive tightening of tuning apparatuses and significantly increases the pressure applied to the drum head and the tuning device. When heavy drumming is done on excessively tensioned heads, the vibration is even more likely to cause shifting, rearrangement, and deformation of the tuning elements, and introduce unwanted binding and overtone suppression.
As illustrated by the Kester patents, drummers have sought a compact, lightweight, easily transportable but finely tunable, high tonal quality drum, but have found it difficult to obtain both easily tunable, high quality sound and a compact, lightweight form. When the drum shell or rim is eliminated from the drum, the tuning must be done in a way that does not require a shell or rim. Until the present invention, no rimless or shell-less drum was tunable without twisting, distorting or binding the frame of the drum head or introducing other problems. Any such deformation reduced the desired depth and richness of tone which up to the present invention could be obtained only with traditional shell drums.
A further step in reducing drum weight occurred with U.S. Pat. No. 4,356,756 to Hartry et al which disclosed a new nontunable but low cost drum head which is known as a pretuned system head or PTS head. The PTS head features a membrane retained by a rigid but small, lightweight frame, with the membrane being tensioned chemically within the frame to provide a single tuned pitch level. The PTS head provided a lightweight, extremely compact playing surface, but its pitch could not be predicted until manufacture of the head was completed.
The PTS head was made using a chemical and heating process which tensioned the membrane during curing to give it a pitch. Each head had to be individually tested after manufacture to determine its pitch, and the pitch continued to change throughout a sixty to ninety day curing period, making the final pitch difficult to predict. The heads had to be classified as low, medium or high pitch range, but wide variations still existed within the ranges.
To speed up the production of PTS heads, a mechanical technique was developed in which the membrane head was mechanically crimped in its frame to thereby create a tensioning of the membrane. This process, described in U.S. Pat. No. 4,549,462 to Donald R. Hartry made the pitch of the PTS immediately ascertainable. This crimping process still resulted in heads which had a wide variation in pitch, and predictability of the pitch was virtually impossible. The need to test heads to classify them as low, medium or high continued, and there was still wide pitch variation in each range. Predictability was further complicated by the discovery that the pitch of the PTS heads was heavily dependent on ambient humidity changes and slightly dependent on changes in ambient temperature. These PTS heads were used as a substitute for standard untuned heads on traditional drum shells and provided a means to market a low cost drum set that required no tuning and appealed primarily to beginning drummers. As a result of all these problems, many drummers, seeking specific, consistent and controllable drum pitch, would not accept the untunable PTS heads.
With the introduction of the resonance isolation mounting system shown in U.S. Pat. No. 4,596,176, it became possible to mount the PTS head without deforming its frame or significantly damping out its tonal quality. The combining of the resonance isolation mounting system with the PTS head improved the sound quality and market appeal of the head significantly and made it highly attractive where mobility was needed. While the tone quality of the PTS head was much improved by the resonance isolation mounting, the pitch of each PTS head remained unpredictable, varied with temperature and humidity, still required individual testing and classification and could not be tuned by drummers.
Of the many drum tuning systems used over the years, the commercially successful ones are the ones that tune from above, are directly accessible, physically and visibly, to the drummer without any bending, kneeling or disassembly. Such access is crucial for fast, convenient tuning during performances. Musicians insist that a tuning system be simple to install, maintain and operate, be absolutely reliable, aesthetically attractive and inexpensive. The tuning system must be capable of holding its tune under even heavy, punishing rock concert conditions. It should have a minimum of parts which are not easily detached or lost, since it may be difficult or impossible to replace parts in time for a critical performance or to quickly obtain replacement parts from out-of-town suppliers. Until the present invention, no satisfactory tuning system had been found for shell-less, rimless drums or PTS heads, and so the weight and size advantages of rimless drums could not be utilized without the sacrifice of tone quality and tunability. For decades, these seemingly opposing requirements have been impossible to satisfy, and the art is a history of compromise and tradeoff between sound quality, bulk, weight, complexity, tuning convenience, cost and other characteristics. The present invention supplies a solution to these problems.